Apparatus for purifying gases and for producing briqueting material.



UNITED STATES PATENT OFFICE.

THOMAS LYN TON BRIGGS, OF FLUSHIN G, NEW YEORK, ASSIGNOR TO GENERALCHEMICAL COMPANY, OF NEW YORK, N. Y., A CORPORATION O F NEW YORK.

APPARATUS FOR PURIFYING GASES AND FOR PRODUCING BRIQUETIN G MATERIAL.

Specification o! Letters Patent.

Patented Apr. 22, 1919.

Original application led .Tune 1, 1916, Serial No. 101.170. Divided andthis application led May l5, 1917.

Serial No. 168,705.

f States patent to'John B. F. Herreshot, No.

556,750, of March 24, 1896, These gases consist of the well knownmixture of sulfur dioxid, oxygen, and nitrogen, with small varyingproportions of sulfur trioxid and dust consisting principally of ironoxid. TheV primary object of my invention is to remove dust contained insuch gases by passing them through a vertically arranged and movablelayer or bediof granular material preferably consisting of the cinderfrom burners of the .type mentioned. The filtered .gases consist ,ofsulfur dioxid, oxygen and nitrogen i and .small varying proportions ofsulfur trioxid and 'onl a very small fraction of the total dustoriginally present. These gases are intended for use either in sulfuricacid manufacture or in the manufacture of sulfitesor bisulfitesin any ofthe old and well known ways. My improvement further contemi'ilates theconversion of the granular filtering.r material, which previously isunfit for hriqueting. nirposes. into a material specially adapted forthe making of brit nets, for4 example by4 the Grndahl K]ellin method,aswex'emplified in United States patent to Gustaf Griindal. No. 780,337of January 17, 1005; these briquets may be used for the production ofiron in a blast furnace. A further object of my invention is to providea simple apparatus whereby the above process may be eflicieutly carriedout and whereby the above mentioned results are attained in an effectivemanner. (lther objects of my improvement will appear from thedescription hereinafter and the features of novelty will he pointed outin the appended claims. This a iplication is a division of anotherapplication filed b v me in the l'nited States Patent Oflicc on June 1.1916, Serial No. 101,170.

In the accompanying drawings I have illustrated bv way of exam ile. oneform of my improved apparatus which has been successfully andpractically utilized. In said drawings Figure 1 is an elevation of aplant including my improved apparatus; Fi '2 is a plan view thereof;y F3 is a vertical section on the lin'e 3-3 of iig. 4; Fig. 4 is a similarview on the line 1 -1 of Fig. 3,

.and F ig. 5 is a detail diagrammatic view on an enlarged scaleillustrating the grate bars and one means whereby said bars areactuated. f

In carrying out my improved process the gases are conducted from vthefurnace and passed, under a suitable pressure, transverselv through avertical' layer of granular material which layer is caused to movegrad-` ,ually downward either practically continuously or intermittentlyat more or less frequent intervals. After having passed through thelayer of granular material the purified gases are suitably conductedaway from the place at which. the purification takes place'. In passinorthrough the said layer of granular imiterial the dust or otherimpurities which it is desired to remove are retained by said materialso that said gases are in the desired purified condition before beingconducted away.

At the same time, as said gases pass through the cinder from a Finesburner, which as before stated is preferred for use as the granularfiltering medium, the said cinder which previously is'unfitfoi-,briqueting purioses, is converted into' a material from wiiclilbriquets may be readily and efficiently iliade. My improved process mayof course be carried out with the aid of any suitable apparatus, theillustrated example having given practical and eilicient results.

As shown in the illustrated example the apparatus comprises a preferablyrectangular chamber 5 constructed for instance of sheet iron and havingan inlet pipe G at one side preferably near the bottom and an outletpipe 7 at the opposite side )referably located near the top of the chamer 5. In the example shown the inlet pipe 6 leads to the top of afurnace 8 which as before stated may he a Fines burner of thellerreshofl.

stationary screen 12 extends across the interior of the chamberpreferably in a d1- rection transversely to the axes of the inlet andoutlet pipes and at a. distance from the 5 inlet pi e 6 as shown in 3.This screen is sulta ly secured in pos1tion and preferably terminates ata. distance from the bottom of' the chamber 5z the illustrated exampleshowin a statlonary plate 13 secured to said ottom and inclimng towardthe space between the screen 12 and said bottom, the upper edge of saidplate 13 being preferably higher than the lower edge of' said screen 12.A second screen 12* also 15 extends across the interior of said chamberand preferably parallel to the first screen and 1s carrie by a, frame 14adJustably mounted in said chamber in such a' manner that the screen 12*,maybe moved toward Y and away from the screen 12 when desired.

The upper and lower portions of the frame 14ans provided respectivelywith lates 15 and 16 the purpose of which wil appear more fullyhereinafter. The screens 12 and 12l may be 'of any mesh Suitablefor the"intended purpose and mayrbeconstructed of any suitable material,screens of one quarter inch mesh of strong iron wire having been foundeliicent in theoperation of my improved process andrapparatus for the`purification of Y burner gases employed in t-he manufacture ofsulful'ieacid by the contactprofcess. At Vits upper;Y end, the chamberis provided with a preferably covered supply hopper 17 whichoIimunicateswith the. space between the twoisereens 12 and 12*v Y while a pluralityof preferabl triangular grate bars 18Y are provided at t ie bottom ofsaid chamberinregist-ry with the s ace be- 40 tween said screens. Itwill be un erstood that the width of the lower end of the hopper 17preferably corresponds to the distance between said screens 124 and 12when at their maximum adjustment away from each 545 other, the gratebars 18 similarly occupyinzg fa space corresponding approximately tothis distance..V A receptacle 19isglocated beneath the grate bars 18 andis provided with an outlet chute 20 controlled by a valve or valves 21,the chamber 5, receptacle 19 and coperatiugparts being all supported* inany -suitablemanner as Vb means of a supporting structure 22. 'liiie sace between the screens 12 and 12 is lille with a granular material 23which pases lfrom the supply lar material 23 which forms a verticalfiltering layer, as before stated, preferably comprises the cnder from aFines burner and is preferably of such a size that it will pass througha one inch mesh sieve but will be retained by a one-quarter inch meshsieve.

Said material 23 may be introduced into the hopper 17 in an suitablemanner as for instance by being ed thereto by means of a conveyer 21from which a chute 25 leads to the interior of said hopper 17.

In operation the gases b the action of the blower 9 pass from the inletpipe 6 into the interior of the chamber 5 and transversely through thescreen 12, anular material 23, and screen 12* and t ien ass out throughthe outlet pipe 7. The sald gases are consequently drawn or otherwisepassed transversely through a vertical wall or bed of granular material,such as the cinders above mentioned, so that *he dust is eilicientlyremoved from said gases in their passage fromthe burner to the flue orother point. The wall or bed of granular material 23 is moved 'downwardbetween the screens 12 and 12 either practically Acon-` tinuously orintermittenti at predetermlned intervals by rocking t le te bars 18. Itwill be understood* that Vsuitable means lwhereby a continuous orpractically 'continuous movement of the bed of granular material isproduced may be provided without de arting from the s iritof-myinvention." he movement oft 1e layer. or bed of filtering .material maybe governed by the indicationsaii'orded by the diii'erential'pressurebetween theinlet and outlet pipes, any increase above the' maximum'pressure desired bein x removed by; 'rocking the grate bars 18 sul'cieiitly'tofclear the passage-ways' for the tO'IexnOve ,the Qlleoteddust. T 1e 'collected'dnst andused granular material 'are deposited in'the receptacle 19 from which they may be removed throu h the chute 20,it :being understood that^tie actuationjof the' grate bars 18 may bebrought about manually for instance by means of the key 18 shown in Fig.5 or by means of any suitable mechanism. As the wall or layer ofmaterial 23 `is caused to descend through an actuation of the' 'gratebars 18 whereby used material is removed from the bottom of said layerof fresh material Vwill be coincidentally added at the top thereof fromthe hopper 17 so that the layer 23 is replenished and the space betweenthe screens 12 and 12* is always maintained full. The hopper 17 is keptsupplied for instance by Ameans of the conveyer 24. y

Byadjust-ing the screen 12* relatively to the screen 12, the thicknessof the wall or layer of granular material 23 may be regulated to meetthe requirements of each specific case, the plates 15 and 16 servingrespectively as a bottom and a cover for those portions of the hopper 17and grate bars 18 ocated behind said screen 12a.

The granular material may also he varied to suit each instance while thetemperature of the gases and their speed through the layer of suchgranular material may also be regulated as desired. As before stated, inan actual operation of the apparatus I have found that a cinder of suchsize that it will pass through a sieve having a one inch mesh ut will beretained by a sieve having a onequarter inch mesh and taken from a Finesburner has given satisfactory and efficient results. In purifying gasesfrom such burner for `use in the manufacture of sulfuric acid gas thethickness of the layer of granular material is preferably about eighteeninches. while the gases are passed therethrough at a temperature ofapproximately 9000 F. and at a speed of from substantially fifteen tosixteenlineal feet per minute, a pressure of g water being sufficientfor this purpose. Under such conditions from 95 to 98% of the oxid ofiron dust contained in the gases is removed therefrom. It will of coursebe understood that the above is only an example and that `the figuresgiven may vary, these depending on the purpose for which the process andapparatus are utilized and the manner in which they are operated. Itwill be readily understood that in place of cinder from a Fines burnerof the Herreshoff type, I can use any equivalent cinder such as can beobtained by suitably crushing and screening cinder from, for example, alump-ore burner.

Then using cinder from a Fines burner as the filtering material, thegases in passing therethrough convert this material from one unfit forthe production of briquets into a material having: specialcharacteristics adapting it for the making of briquets. In this mannerthe cinder after having fully served its purpose as a filtering mediummay be formed into useful briquets instead of being discarded as wastematerial.

The temperature of the gas While undergoing purification as describedshould be neither too high nor too low and should preferably besomewhere between a minimum temperature slightly above that at whichsubstances harmful to the material of which the apparatus is constructedbegin to condense out and attack said apparatus and a maximumtemperature just below that at which the gas produces material such assulfuricanhydrid. The minimum perature of thc gas being treated may efrom 680 to 7500 F. within which range the gas will be purified withoutcausing any abnormal, unusual or avoidable injury to the material ofwhich the apparatus is constructed and the filtering material will showsome improvement as a briqueting material. The maximum temperature ofsaid gas may be approximately 900C F. at which dust is eliicientlyremoved from the gas without bringing about any condensation harmful tothe apparatus and with a maximum of improve- .ment in the filteringmaterial as a briqueting substance. At ythis latter temperature aminimum and practically negligible quantity of sulfuric anhydrid isproduced in the exit gas. lVhenever conditions warrant it I thereforeprefer to maintain the gas, during the purification thereof, atapproximately the temperatl'ire last indicated.

It will be apparent from the above that, according to the temperatureselected for the gas, purification alone may be effected, or bothpurification of the gas and maximum improvement of the filteringmaterial for briqueting purposes may be accomplished while at the sametime any intermediate results as to the change in the characteristics ofthe filtering material ma be produced by simply passing the as terethrough at the temperature wherey the desired results will beobtained.

fhile my apparatus is specially adapted for purifying gases which areafterward converted into sulfuric acid, said apparatus is not limited tothis use but may be advantageously and efficiently used in many otherconnections.

Various changes in the specific apparatus described may be made withinthe scope of the claims without departing from the spirit of myinvention.

I claim:

1. An apparatus of the kind described comprising a chamber having aninlet and outlet, a pair of vertical screens spaced from each other andlocated in said chamber between said inlet and outlet, a layer ofgranular material in the space between said screens, said layerextending from the top to the bottom of said chamber, a series of gratebars in the bottom of said chamber in registry with the space betweensaid screens whereby material may be removed from the bottom of saidlayer and a hopper at the top of said chamber communicating with thespace between said screens whereby said layer may be coincidentallyreplenished at the top.

2. An apparatus of the kind described comprising a chamber having aninlet and outlet, a pair of vertical screens spaced from each other andlocated in said chamber bet-Ween said inlet and outlet, a layer ofgranular material in the space between said screens, said layerextending from the top to the bottom of said chamber, means forvibrating said layer to remove material from the bottom thereof, meansfor coincidentally replenishing said layer at the top and a receptaclebeneath said chamber adapted to receive the material removed from thebottom of said layer.

3. An apparatus of the kind described comprising a chamber having aninlet and an outlet, a stationary vertical screen in said chamberbetween said inlet and outlet. an adjustable vertical screensubstantially parallel with said stationary screen, a movable framecarrying said adjustable screen whereby the latter may be moved towardand away from said stationary screen, a layer of gjlfranular` materialin the space between said screens and extending from the top to thebottom of said chamber, a series of grate bars in the bottom of saidchamber whereby N:aid layer of material may be shaken down, a hopper at.the top of said chamber whereby 1:) said layer may be replenished at thetop and moved.

In testimony whereof I have hereunto set my hand.

THOMAS LYNTON BRIGGS.

